/// <summary>

    /// WaterMarkHandlher 的摘要说明

    /// </summary>

    public class WaterMarkHandlher : IHttpHandler

    {

        static string waterPath = "~/image/watermark.png"; //水印图片路径

        static string defaultPath = "~/image/default.jpg"; //默认图片路径

        public void ProcessRequest(HttpContext context)

        {

            string coverPath = context.Server.MapPath(context.Request.Path);

            Image coverImage;

            //如果文件不存在则加载默认图片

            if (!File.Exists(coverPath))

            {

                coverImage = Image.FromFile(context.Server.MapPath(defaultPath));

            }

            //图片存在

            else

            {

                //加载图片

                coverImage = Image.FromFile(coverPath);

                //加载水印

                Image water = Image.FromFile(context.Server.MapPath(waterPath));

                //实例化画布

                Graphics g = Graphics.FromImage(coverImage);

                //绘制水印

                g.DrawImage(water,

                    new Rectangle(coverImage.Width - water.Width, coverImage.Height - water.Height, water.Width,

                        water.Height), , , water.Width, water.Height, GraphicsUnit.Pixel);

                //释放画布

                g.Dispose();

                //释放水印

                water.Dispose();

            }

            context.Response.ContentType = "image/jpeg";

            coverImage.Save(context.Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg);

            coverImage.Dispose();

            context.Response.End();

        }

        public bool IsReusable

        {

            get

            {

                return false;

            }

        }

    }